1. Field of the Invention
This invention relates to a method of manufacturing an integral key top type contact rubber structure including a multiplicity of push keys, which is usable with a variety of apparatus which are so designed that inputting is effected through manipulation of buttons.
2. Description of the Prior Art
Referring to FIG. 1, there is shown a conventional push key assembly including a contact rubber structure 1 which supports key tops 2 each formed of a material which is harder than that of the contact rubber structure, by means of a frame 3. Indicated at 4 are electrodes printed on a printed circuit board 5.
Disadvantageously, however, the above conventional push key assembly, when it is to be formed, requires time-consuming and troublesome procedures in that variously colored key tops should be chosen, arranged on the contact rubber structure and then supported by means of the frame. Another disadvantage is that the prior-art assembly is not satisfactory in its water-proof and dust-proof properties.